Elevator system with temporary hoistway structure and method for use thereof

ABSTRACT

An elevator system in which a temporary hoistway is formed in an open air shaft of a building under construction. The hoistway members, which in turn support the guide rails, are connected to the building members in a manner that, upon forces being exerted on the guide rails, these forces are distributed to several levels of the building. The buffer assembly for protection against downward overtravel is connected to the rails and is movable upward as construction progresses. A method of using this arrangement to provide passenger elevator service into unaligned steelwork of a building under construction is also described.

United States Patent 1 Siefr'ert Sept. 18, 1973 [75] Inventor: Joseph Edward Sieifert, New Hyde Park, NY.

[73] Assignee: Otis Elevator Company, New York,

[22] Filed: Mar. 13, 1972 [21] Appl. No.: 234,058

[52] U.S. Cl 187/2, 187/67, 187/95 [51] Int. Cl 8661) 9/00 [58] Field of Search 187/2, 6, 67, 809 C;

526,207 10/1920 France ..187/67 Primary ExaminerEvon C. Blunk Assistant ExaminerMerle F. Maffei Attorney-Joseph L. Sharon et al.

[57] ABSTRACT An elevator system in which a temporary hoistway is formed in an open air shaft of a building under con struction. The hoistway members, which in turn support the guide rails, are connected to the building members in a manner that, upon forces being exerted on the guide rails, these forces are distributed to several levels of thebuilding. The buffer assembly for protection against downward overtravel is connected to-the rails and is movable upward as construction progresses. A method of using this arrangement to provide passenger elevator service into unaligned steelwork of a building under construction is also described.

9 Claims, 6 Drawing Figures Patented Spt. 18, 1973 2 Shee ts-Sheet l FIG.6

Patented Sept. 18, 1973 2 Sheets-Sheet 2 1 ELEVATOR SYSTEM WITH TERARY HOISTWAY STRUCTURE AND METHOD FOR USE THEREOF This invention relates to elevators and particularly to elevators suitable to carry workmen to their jobsites in the upper levels of buildings still under construction.

In the past, workmen in buildings still under construction have been provided elevators by erecting them in the permanent hoistways of such buildings while they are still at a relatively low level of construction. The travel of these elevators is then extended upwardly in their respective hoistways as their buildings construction progresses. The rise of these elevators, unfortunately, is typically restricted to a level up to eight or nine floors below the uppermost level under construction because the erection of the guide rails in completing a permanent hoistway awaits the final alignment of a buildings constuctural steel members and this is usually performed in stages of eight or nine floors at a time.

Thus, while elevators which are erected in permanent hoistways do perform a valuable service, they do not follow high rise building construction closely enough to serve those construction people, such as the steel workers, whose jobs require their presence at the uppermost levels of construction. As a result, these workers normally are only provided elevator service to a level which is still quite a number of stories below that at which they are working. Today with workers being paid for virtually all on-site time, expeditious methods are being sought to transport them closer to their work.

The elevator arrangement disclosed in U.S. Pat. No. 3,519,101 granted Joseph E. Sieffert on July 7, 1970 is employed with the presently disclosed equipment. This arrangement enables the rise of an elevator to be increased without the necessity of reroping which makes it quite desirable for use in buildings still under construction. As disclosed in the Sieffert patent, however, this arrangement contemplates for use as a hoistway an area of a building which will serve as one of the buildings permanent elevator hoistways. As employed in practice, this arrangement does not extend service above a level at which its guide rails are supported in their permanently aligned manner. As a result, its rise is limited to that portion of a building in which the structural steel is finally aligned. Otherwise, the elevator would probably have to be put out of service at various intervals to permit the realignment of its guide rails to match the final alignment of the structural steel members from which they are supported. This is hardly acceptable.

Alternatively, the guide rails might be supported in a temporary manner from unaligned steel whereby the final rail alignment might possibly be postponed until all the building steel is finally aligned. This, however,

would mean that the completion of that hoistway would probably be unduly delayed since it is not apparent how that hoistway could be made available for alteration to its permanent condition until the elevator was no longer required. Also, since for safety reasons a passenger hoistway has to be enclosed, supporting the rails in a temporary manner from unaligned steel would necessitate the use of temporary walls on those levels on which the steel is not finally aligned. The use of temporary walls to enclose a permanent hoistway is also an unsatisfactory arrangement. With such, either the service provided by the elevator would have to be interrupted at various intervals to permit the removal of the temporary walls and the installation of the permanent ones or the installation of the latter would have to be unduly delayed until such time as the service provided by the elevator was no longer needed.

As is evident from the foregoing, an arrangement which utilizes one of a buildings permanent elevator hoistways is not a completely satisfactory one for providing elevator service to the unaligned steel portions of the building during its construction. It is, therefore, desirable to utilize a vertically open area of a building other than the permanent hoistway area in which to provide such service. The use of this area as a temporary hoistway would, of course, prevent the completion of floors where located unless the elevator arrangement provided for utilizing this area was such that its lower terminal could be raised as the building progressed upwardly. This would thereby free these open floor areas for completion of construction.

One of the problems which could be foreseen with such an arrangement involved the provision of suitable car and counterweight buffers which in traction elevator installations serve to bring the car and counterweight to rest in case of overtravel beyond the lower terminal landing. In a typical installation the car buffer, and occasionally the counterweight buffer as well, is supported by heavy steel members mounted directly on the building foundation. Where the counterweight buffer is suspended from the counterweight, a bumper block is mounted on the foundation to receive the impact of the counterweight buffer in case of overtravel. In installations in which either the car and counterweight buffers or a bumper block are supported in an area of a building above its foundation, the anticipated forces on this equipment cause erectors to shore up with additional columns the structural elements supporting the equipment. It is desired that the arrangement for enabling the raising of the lower terminal as the building is erected avoid the necessity of shoring up with additional columns those structural elements supporting the car and counterweight buffers or bumper block at each new location thereof.

It is an object of the present invention to provide an improved elevator for use during the construction of a building.

Another object is to provide an elevator which is capable of carrying workmen up into the unaligned steelwork portion of a building.

A feature of the present invention is that the lower terminal of the elevator can be shifted upwards as the building progresses.

Another feature of the invention is that the forementioned temporary hoistway arrangement lends itself to the utilization of preassembled units. This reduces installation labor resulting in a consequent saving in time and money over the installation of nonassembled units in a permanent hoistway.

In carrying out this invention, an elevator is provided which is suitable for use in a building under construction by erecting within a vertical air shaft of the building a temporary hoistway that has its lower terminal adjustably determined by a movable buffer assembly. The air shaft, at a location that differs from the permanent elevator hoistway, is defined by horizontal structural members which form the floor levels of the building. The temporary hoistway therein is formed by a plurality of pairs of vertically flexible members, each pair of which for convenience may be included within a frame, secured to the horizontal structural members in a predetermined manner about a vertical axis and by elevator car guide rails that are fixed to and interconnect the pairs of vertically flexible members or buffer frames. A buffer assembly is releasably engaged to the rails below the lower terminal and supports the buffer thereon. The points at which the rails are attached are located on the vertically flexible members so that forces exerted on the rails are transmitted to the horizontal structural members on several floor levels of the buildmg.

Other objects, features and advantages of the invention will become apparent from the following description and appended claims when considered in conjunction with the accompanying drawing, wherein like parts are designated by like numerals throughout the several views, and wherein:

FIG. 1 is a pictorial view showing the application of the invention to an elevator system useful during the construction of a building;

FIG. 2 is an isometric view showing a movable elevator car buffer assembly and the underside of an elevator car;

FIG. 3 is a fragmentary view showing details of the movable buffer assembly of FIG. 2;

FIG. 4 is an isometric view showing a frame member used in assembling the temporary hoistway of the system of FIG. 1;

FIG. 5 is a fragmentary view showing details of a unit used in securing the frame member of FIG. 4 to a building structure; and

FIG. 6 is a fragmentary view showing details of another unit used in securing the frame member of FIG. 4 to a building structure.

Referring primarily to FIG. 1, there is shown an elevator system having a plurality of like rectangular frames 21 (FIG. 4), each mounted atop and secured to horizontal structural first members 22 of a building framework. These first members together form a suitable vertical air shaft extending through several floor levels of a building. Each of frames 21 may be disposed in the same relative position about the longitudinal axis 23 of the air shaft.

Frames 21 are interconnected by being connected to elevator car guide rails 24 in any satisfactory manner such as by typical rail clips. Guide rails 24 comprisea plurality of rail sections suitably joined together. These guide rails 24 guide elevator car 25 which is equipped with overspeed safety mechanism (not shown) in the normal fashion. Frames 21 and a pair of vertically extending guide rails 24 together form a temporary'hoistway for the elevator car. The upper and lower terminals within this temporary hoistway are defined by the positions of movable car buffer assembly 31 and portable machine room 32.

Elevator car buffer assembly 31 (FIG. 2) is connected across guide rails 24. A second typical elevator car safety mechanism, distinct from that used for overspeed protection, is modified to mount the buffer. This arrangement includes buffer frame 35 and a pair of rail engagement assemblies 36. Mounted atop the buffer frame 35 is at least one buffer 34 which in this particular embodiment is illustrated as a pair of spring buffers 34 although oil buffers are also suitable. While any sufficiently strong crosspiece connected between guide rail 24 might be satisfactory for mounting the buffer, the modified safety mechanism disclosed herein is particularly convenient.

Counterweight 45 is guided by counterweight guide rails 46 (FIG. 1) which are suitably attached to hoistway frames 21. counterweight 45 is roped 2:1 (as is car 25) by means of detachable sheave assembly 49 which is also guided by rails 46. A counterweight buffer assembly (not shown) is provided for the counterweight 45 but is not described in detail as it is similar to elevator car buffer assembly 31, except for being adapted to the dimensions of rails 46.

Each spring buffer 34 (FIG. 2) of elevator car buffer assembly 31 comprises buffer spring 60 and spring mount 61. These are supported atop upper channel beam 62, the uppermost element of a substantially rectangular buffer frame 35. Buffer frame 35 also includes lower frame beam 63. At each corner of the buffer frame 35 and extending outwardly therefrom is a notched guide shoe 64 for cooperation with its respective rail 24.

Connected to each side of upper channel beam 62 is a pair of rail engagement assemblies 36 for releasably attaching buffer assembly 31 to guide rails 24. Each of these assemblies comprises spring-loaded lever arm 65, linkage rod 66, roller 67 (FIG. 3), and safety block 68 (FIG. 3). Vertical supports 69 of buffer frame 35 are fastened between upper channel beam 62 and lower frame beam 63. Cross brace 70 is connected between supports 69.

Each lever arm 65 is pivotally connected at a point intermediate its two ends to a different one of vertical supports 69. One end of each lever arm is connected to spring biasing unit 71, each of which is attached to cross brace 70. The other end of each lever arm 65 is connected through linkage rod 66 to roller 67 retained within roller-retaining cavity 72 of safety block 68. In this way, roller 67 is urged into engagement with its associated rail 24 by being forced up the wedge-shaped channel formed by the inclined surface 73 of safety block 68 and the surface of guiding web 74 of guide rail 24. This wedging of the roller between safety block and rail at a predetermined vertical location along the guide rail 24 is achieved by the force of spring biasing unit 71 being applied to the roller 67 through arm 65 and rod 66. Forces applied to the buffer assembly are thereby transmitted to guide rails 24. Engagement releasing brackets 75 are attached to the underside of upper channel beam 62, a different one for cooperating with each lever arm 65. Each lever arm can be detachably coupled to its respective bracket whereby the associ ated rail engagement assembly 36 is retained in a released position with its roller 67 out of engagement with the associated rail 24 so that buffer assembly 31 may be readily moved to changeits vertical location. To facilitate buffer movement, upper channel beam 62 is also adapted to engage eyebolts 76 which may be attached to the underside of car 25 by means of brackets 77 and pins 78.

An illustrative one of frames 21, shown in detail in FIG. 4, includes a pair of horizontally disposed I-beams 80. These I-beams rest on and are suitably fastened to short I-beam sections 79 which are mounted on horizontal structural first members 22. Suitably, I-beams 80 and horizontal structural members 22 are at right angles to each other. I-beam sections 79 may be secured to the building by any of several suitable attaching means which would satisfactorily join them to horizontal structural members 22. Each frame 21 includes a pair of horizontally disposed vertically flexible second members 81, which second members are disposed in substantially the same relative position to the longitudinal axis 23 of the air shaft. In this disclosed embodiment, vertically flexible second members 81 comprise channel beams on opposite sides of the frame 21 having longitudinally extending upwardly disposed plates 82 welded thereto. Each of vertically flexible second members 81 is mounted atop a respective l-beam 80 and is in substantial vertical alignment with corresponding ones of other frames 21 in that the longitudinal axes of corresponding second members 81 are parallel to and coplanar with each other. The corresponding substantially vertically aligned second members 81 are thereby formed into two sets, of which each set is in a separate plane, which in turn has longitudinal axis 23 parallel to it. Each vertically flexible second member 81 is separated from its respective I-beam 80 a predetermined amount by a pair of securing means of the type illustrated in FIG. 5. The distance between securing means establishes an active span of prescribed length. This active span of each side'member 81 provides it with its vertically flexible characteristic and determines the amount the member will deflect under a given amount of force applied thereto. Each elevator car guide rail 24 (FIGS. 1 and 2) is connected in any suitable manner to members 81 at approximately the midpoint of their active spans.

Frame members 83 and 84 joining the members 81 at the front and rear thereof, which may take any suitable shape, are fastened to the ends of each side member 81 by endplates 85 which are welded to their respective front and rear members. Angles 86 and braces 87 are attached to the underside of rear frame member 84 in predetermined locations to form rail mounting brackets enabling counterweight rails 46 (FIGS. 1 and 2) to be supported thereon and to interconnect rear frame members 84.

The securing means shown in FIG. 5 secures members 81 to l-beams 80 at each end of the active span of each member 81. L-shaped strap 91 is bolted to side member 81 through plate 82. Spacer 92 between the bottom of member 81 and the top of I-beam' 80 is bolted to the leg of strap 91 and clamped to the flange of beam 80 by clamping plate 93. The rear ends of members 81 are secured to beams 80 through the use of flat straps 94 (F IG. 6) which are located above and below the top and bottom flanges of I-beam 80. These straps are bolted together and the upper strap of each of these corner securing means also is clamped to the outside bottom surface of the upper flange of its respective beam 80 by clamping plate 95(The inner bolt holding the bottom and top straps together passes through beam 84 and a nut fastens it to the upper surface thereof.

To understand how the above-disclosed elevator system is used in a building under construction, assume that the system is to be installed in a building having a steel framework. As soon as the building steel, which includes horizontal structural members 22 of the first four floor levels, is self-supporting but not necessarily aligned, beam sections 79, I-beams 80 and the rest of a frame 21 (FIG. 4) are installed on each floor, in the previously disclosed manner, at the designated air shaft in substantially similar alignment with longitudinal axis 23 (FIG. 1). Elevator car rails 24 are attached to the vertically flexible members 81 of frame 21, as disclosed, to extend below the first floor level and counterweight rails 46 are attached to angles 86 (FIG. 4). Car bufier assembly 31 and the counterweight buffer assembly (not shown) are positioned between their respective rails 24, 46 at the desired lower end of travel and their modified safety mechanisms are released causing both buffer assemblies to engage their respective guide rails. Preassembled elevator car 25 and counterweight 45 are hoisted into place and landed on their respective bufier assemblies. Portable machine room 32, including the typical traction drive equipment, is lifted into place by the contractors crane and is suitably positioned on machine beams on the fourth floor level. As additional steel is erected floor by floor, workers install additional frames 21 together with their associated beam sections and I-beams. With the installation of each group of two frames 21, rails 24 and 46 are installed and roughly aligned. Suitable hoistway enclosing panels are installed to protect personnel from the otherwise open shaft. When the temporary hoistway reaches a specified level above the top floor to which service is initially desired (two floors above the top floor being deemed satisfactory), the machine room is hoisted to that level by the contractors hoist and the elevator installation is completed in accordance with the procedure disclosed in the forementioned U.S. Pat. No. 3,519,101.

When the temporary hoistway reaches a level two floors above a new top floor to which it is desired to extend service, the elevator system is extended by hoisting up the portable machine room 32 to that new level and paying out the ropes as described in the aforementioned patent. This extension procedure may be followed until normal elevator service is available at the lower landings of the building and the need to service these lower landings with the herein disclosed system no longer exists. Then, the rise can either be shortened or the entire elevator system can be raised as a unit. In the latter case, when crane capacity is adequate, the hoist may be used to raise to the desired level the portable machine room 32 with its elevator car 25 attached as in U.S. Pat. No. 3,519,101 and with buffer assembly 31 attached to car 25 by eyebolts 76 together with counterweight 45 and its buffer assembly attached thereto in similar fashion.

Where crane capacity is insufficient for lifting this equipment as a unit in the manner just mentioned, counterweight 45 may be positioned on and attached to its buffer assembly and detached from sheave assembly 49. The counterweight and its buffer assembly may then be raised after the other equipment in a separate hoisting operation. Reattachment of the counterweight to sheave 49 takes place after its buffer assembly is repositioned and it is disconnected therefrom.

To shorten the rise (such as when the building construction has advanced to the point at'which the topmost steel is in position and completion of floor areas at the lower levels of the disclosed elevator system is scheduled), the following operational procedure is followed. Weights are placed on car 25 so that the total weight of the car and these extra weights exceed the combined weight of counterweight 45 and its buffer assembly. Then, counterweight 45 is positioned on and attached to the counterweight buffer assembly which is then moved to its new position by operating car 25 in the downward direction. Thereafter, the counterweight buffer assembly is placed in re-engagement with rail 46 and the counterweight is disconnected therefrom. Car 25 is then further lowered so that it rests on its buffer. After being attached thereto by eyebolts 76, car 25 is now raised. If the rise is being shortened less than half, then the car is stopped in its upward operation when its buffer assembly reaches its new location. At that point, the car and its buffer assembly are disconnected after the latters lever arms 65 are detached from brackets 75 to enable rollers 67 to re-engage rails 24. Counterweight 45 is then bottomed and car 25 is hoisted to its top terminal by the contractors crane, during which operation the excess hoist ropes are reeled back into storage and reclamped at their new length in accordance with the above mentioned U.S. Pat. No. 3,519,101. If the rise is shortened more than half, the counterweight bottoms before the cars buffer assembly reaches its new location, under which circumstances the crane is used to lift it together with the car to the formers new location While the hoist ropes are reeled back into storage. Upon being positioned at its new location, the buffer assembly is disconnected from the car and the latter is hoisted to the top terminal as previously explained.

Upon establishing a higher lower terminal for the elevator system, portions of the temporary hoistway are removed and floor areas in the vertical air shaft are completed.

A previously unmentioned feature of the invention is the ability of the temporary hoistway structure to distribute vertical forces transmitted to the rails from buffer assembly 31 in the event of overtravel or from the normal car safety (not shown) in case of operation thereof in the event of overspeeding. This distribution is through a plurality of frames 21 to the building's structural elements 22 on a plurality of floors. The distribution permits the frames to be of lighter weight than they could be if such forces are not distributed since no single frame has to sustain the maximum safe load for which the rails are rated. In fact, the frames are designed so that the maximum force any frame will have to sustain is predetermined. This is accomplished, as desired, by selecting the deflection per unit of force of the active span of each vertically flexible member 81 accordingly. Thus, if guide rails 24 are No. 1 rails with a maximum rated safe loading of 15,000 lbs. and if it is desired that no frame 21 and therefore no building floor level sustain more than an 8,000 lb. load notwithstanding a 15,000 lb. vertical force may be applied to each of rails 24, member 81 should be provided with an active span which will deflect sufficiently so that in conjunction with the elongation of the guide rails 11/15 or 73% percent of any load applied to any one frame through a rail will be transmitted to the other frames of the structure. The design of structural members to accomplish this purpose is performed by straightforward structural design techniques well known to any structural designer and, for purposes of brevity, will not be explained herein.

Modifications in the disclosed arrangement are possible and for that reason the foregoing should be understood to be illustrative and not limitingin any sense.

What is claimed is:

1. An elevator system within a building framework having a plurality of horizontal structural first members defining a vertical air shaft and several floor levels, said elevator system comprising an elevator car having a safety mechanism mounted thereon; a pair of guide rails each extending said several floor levels for guiding said elevator car; each said guide rail comprising a plurality of interconnected rail sections; said elevator car safety mechanism operating in the event of an overspeeding condition and applying vertical forces to said guide rails; and a plurality of pairs of substantially parallel horizontally disposed, vertically flexible second members, each pair of said second members mounted on a pair of first members at a different one of said several floor levels, each member of each pair of said second members being'in substantial vertical alignment with and having its longitudinal axis substantially in the same plane with and parallel to that of the corresponding members of the other such pairs thereby forming two sets of said members, each set of vertically aligned second members being connected to and interconnected by a different one of said guide rails, thereby forming a temporary hoistway structure; said temporary hoistway structure distributing vertical forces applied to said guide rails to a plurality of said structural members on several of said floor levels.

2. An elevator system in accordance with claim 1, including a buffer assembly having a buffer frame with a buffer mounted thereon and rail engagement means releasably engaging said buffer frame tosaid guide rails, said buffer assembly being held in engagement with said guide rails at a predetermined vertical location thereof whereby forces exerted on said buffer inthe event of overtravel of said car are applied to said guide rails.

3. An elevator system in accordance with claim 2, wherein said rail engagement means includes a pair of safety blocks, each cooperating with a different one of said guide rails, each safety block including a cavity having an inclined surface and receiving the guiding web of its associated rail, a roller retained in each of said cavities and wedged between the guiding web of its associated rail and said inclined surface thereby holding said buffer assembly in engagement with said guide rails at said predetermined vertical location.

4. An elevator system in accordance with claim 3, wherein each said rail engagement means includes a spring biased lever arm pivotally connected at a point intermediate its two ends to said buffer frame andv a linkage connected at one end to its associated roller and at the other end to said lever arm whereby said roller is urged into engagement with its associated inclined surface and guide rail web.

5. An elevator system within a'building framework having a plurality of horizontal structural members defining a vertical air shaft and several floor levels, said elevator system comprising an elevator car; a pair of rails extending vertically said several floor levels for guiding said elevator car; each said pair including a plurality of interconnected rail sections; a plurality of frames, each having a pair of vertically flexible members, each of said frames secured to those horizontal structural members defining a different one of said several floor levels and having its vertically flexible members disposed in substantially the same relative position to the longitudinal axis of said air shaft, each similarly disposed flexible member of said frames being inter connected by one of said vertically extending rails, thereby forming a temporary hoistway structure; and a buffer assembly, including a buffer frame and a buffer mounted on the top thereof, attached to said rails, said buffer assembly transmitting to said rails vertical forces exerted on said buffer in the event of overtravel by said car, said temporary hoistway structure distributing vertical forces applied to said rails to a plurality of said structural members on several of said floor levels.

6. An elevator system in accordance with claim 5, wherein said buffer assembly includes a pair of rail engaging means mounted one on each side of said buffer frame, each said rail engaging means releasably attaching said buffer assembly to an associated rail.

7. An elevator system in accordance with claim 6, wherein securing means secures each of said frames to its associated horizontal structural members and establishes an active span for each of the vertically flexible members of said frame, said active span determining the amount the member deflects under a given amount of force applied thereto through its associated rail, each rail being connected to its associated flexible members at substantially the midpoint of the active span of each.

8. A traction elevator system for transporting construction workers into the unaligned steelwork of a building under construction, said building having a steel framework with horizontal structural members defining a vertical air shaft and several floor levels, said elevator system comprising an elevator car; a pair of car guide rails for guiding said elevator car; each said car guide rail comprising a plurality of interconnected rail sections; a counterweight; a pair of counterweight guide rails for guiding said counterweight; traction drive means for driving said elevator car and said counterweight; a plurality of substantially identical rectangular frames, each having first and second opposite sides, each of the first opposite sides of each frame having vertically flexible channel members atop thereof, the second opposite sides of each frame joining their respective first opposite sides at the front and rear thereof, a pair of rail mounting brackets for said counterweight guide rails mounted on the rearward side of each frame, first securing means attaching each channel member to the top of its respective first opposite side and maintaining a predetermined amount of separation therebetween throughout a described length, said amount of separation and said prescribed length establishing the amount of vertical flexure, each said channel members undergoes in response to a given amount of vertical force applied thereto, second securing means attaching each of said rectangular frames to the horizontal structural members at a different one of said several floor levels, each of said rectangular frames being disposed in substantially the same orientation relative to the longitudinal axis of said air shaft; mounting means connecting one of said car guide rails at substantially the midpoint of the prescribed length of each channel member on each side of said frames, thereby interconnecting said channel members on each side by said car guide rails, the vertical flexibility of said channel members being so related to the elongation of said car guide rails that vertical forces applied to said rails are distributed through said frames to a plurality of horiii izontal structural members on several of said floor levels; means mounting said counterweight rails on said rail mounting brackets, thereby interconnecting said rearward sides of said frames by said counterweight guide rails; and car and counterweight buffer assemblies, each positioned between its respective guide rails and held in releasable engagement therewith, each of said buffer assemblies having a bufi'er mounted atop a substantially rectangular buffer frame at the corners of which, and extending outwardly therefrom, are notched guide shoes for cooperation with the respective guide rails; each buffer assembly including a pair of rail engagement assemblies, one mounted at each upper corner of its respective frame, each rail engagement assembly comprising a safety block having in the outer face thereof a roller retaining cavity receiving the guide web of its respective guide rail, a roller within said cavity, a lever arm pivotally connected at a point intermediate its ends to said buffer frame, a linkage rod, one end of which is connected to said roller and the other end of which is connected to one end of said lever arm, the other end of said lever arm being spring biased, thereby urging said roller into engagement with its respective guide rail web and one of the walls of its cavity; and an engagement releasing bracket mounted on said bufier frame for holding said roller out of engagement with its guide rail web against the tension of said spring biased lever arm.

9. A method of providing passenger elevator service into the unaligned steelwork of a building under construction, said building having a framework with a plurality of horizontal structural elements which define a vertical air shaft and a plurality of floor levels, said method comprising the steps of placing a pair of substantially parallel horizontally disposed, vertically flexible members on the horizontal structural elements which define predetermined ones of said plurality of floor levels; disposing each member of each of said pairs in substantial vertical alignment with and with its longitudinal axis substantially coplanar with and parallel to that of the corresponding members of the other such pairs thereby forming two sets of said members; securing said sets of members to said horizontal structural elements; fastening an elevator car guide rail, comprising a plurality of interconnected rail sections, to the members of each of said sets thereby interconnecting the separate members of each of said sets and forming a temporary hoistway; releasably engaging a buffer assembly including an elevator car buffer to said elevator car guide rails sufficiently to remain stationary under the application of forces to said buffer resulting from the overtravel of its elevator car, thereby establishing a lower terminal for said elevator car; installing traction elevator equipment including an elevator car operable to travel in said temporary hoistway; raising, as building construction progresses upwardly, said buffer assembly to establish a higher lower terminal for said elevator car; and removing portions of said temporary hoistway structure then located below said higher lower terminal. 

1. An elevator system within a building framework having a plurality of horizontal structural first members defining a vertical air shaft and several floor levels, said elevator system comprising an elevator car having a safety mechanism mounted thereon; a pair of guide rails each extending said several floor levels for guiding said elevator car; each said guide rail comprising a plurality of interconnected rail sections; said elevator car safety mechanism operating in the event of an overspeeding condition and applying vertical forces to said guide rails; and a plurality of pairs of substantially parallel horizontally disposed, vertically flexible second members, each pair of said second members mounted on a pair of first members at a different one of said several floor levels, each member of each pair of said second members being in substantial vertical alignment with and having its longitudinal axis substantially in the same plane with and parallel to that of the corresponding members of the other such pairs thereby forming two sets of said members, each set of vertically aligned second members being connected to and interconnected by a different one of said guide rails, thereby forming a temporary hoistway structure; said temporary hoistway structure distributing vertical forces applied to said guide rails to a plurality of said structural members on several of said floor levels.
 2. An elevator system in accordance with claim 1, including a buffer assembly having a buffer frame with a buffer mounted thereon and rail engagement means releasably engaging said buffer frame to said guide rails, said buffer assembly being held in engagement with said guide rails at a predetermined vertical location thereof whereby forces exerted on said buffer in the event of overtravel of said car are applied to said guide rails.
 3. An elevator system in accordance with claim 2, wherein said rail engagement means includes a pair of safety blocks, each cooperating with a different one of said guide rails, each safety block including a cavity having an inclined surface and receiving the guiding web of its associated rail, a roller retained in each of said cavities and wedged between the guiding web of its associated rail and said inclined surface thereby holding said buffer assembly in engagement with said guide rails at said predetermined vertical location.
 4. An elevator system in accordance with claim 3, wherein each said rail engagement means includes a spring biased lever arm pivotally connected at a point intermediate its two ends to said buffer frame and a linkage connected at one end to its associated roller and at the other end to said lever arm whereby said roller is urged into engagement with its associated inclined surface and guide rAil web.
 5. An elevator system within a building framework having a plurality of horizontal structural members defining a vertical air shaft and several floor levels, said elevator system comprising an elevator car; a pair of rails extending vertically said several floor levels for guiding said elevator car; each said pair including a plurality of interconnected rail sections; a plurality of frames, each having a pair of vertically flexible members, each of said frames secured to those horizontal structural members defining a different one of said several floor levels and having its vertically flexible members disposed in substantially the same relative position to the longitudinal axis of said air shaft, each similarly disposed flexible member of said frames being interconnected by one of said vertically extending rails, thereby forming a temporary hoistway structure; and a buffer assembly, including a buffer frame and a buffer mounted on the top thereof, attached to said rails, said buffer assembly transmitting to said rails vertical forces exerted on said buffer in the event of overtravel by said car, said temporary hoistway structure distributing vertical forces applied to said rails to a plurality of said structural members on several of said floor levels.
 6. An elevator system in accordance with claim 5, wherein said buffer assembly includes a pair of rail engaging means mounted one on each side of said buffer frame, each said rail engaging means releasably attaching said buffer assembly to an associated rail.
 7. An elevator system in accordance with claim 6, wherein securing means secures each of said frames to its associated horizontal structural members and establishes an active span for each of the vertically flexible members of said frame, said active span determining the amount the member deflects under a given amount of force applied thereto through its associated rail, each rail being connected to its associated flexible members at substantially the midpoint of the active span of each.
 8. A traction elevator system for transporting construction workers into the unaligned steelwork of a building under construction, said building having a steel framework with horizontal structural members defining a vertical air shaft and several floor levels, said elevator system comprising an elevator car; a pair of car guide rails for guiding said elevator car; each said car guide rail comprising a plurality of interconnected rail sections; a counterweight; a pair of counterweight guide rails for guiding said counterweight; traction drive means for driving said elevator car and said counterweight; a plurality of substantially identical rectangular frames, each having first and second opposite sides, each of the first opposite sides of each frame having vertically flexible channel members atop thereof, the second opposite sides of each frame joining their respective first opposite sides at the front and rear thereof, a pair of rail mounting brackets for said counterweight guide rails mounted on the rearward side of each frame, first securing means attaching each channel member to the top of its respective first opposite side and maintaining a predetermined amount of separation therebetween throughout a described length, said amount of separation and said prescribed length establishing the amount of vertical flexure, each said channel members undergoes in response to a given amount of vertical force applied thereto, second securing means attaching each of said rectangular frames to the horizontal structural members at a different one of said several floor levels, each of said rectangular frames being disposed in substantially the same orientation relative to the longitudinal axis of said air shaft; mounting means connecting one of said car guide rails at substantially the midpoint of the prescribed length of each channel member on each side of said frames, thereby interconnecting said channel members on each side by said car guide rails, the vertical flexibility of said chaNnel members being so related to the elongation of said car guide rails that vertical forces applied to said rails are distributed through said frames to a plurality of horizontal structural members on several of said floor levels; means mounting said counterweight rails on said rail mounting brackets, thereby interconnecting said rearward sides of said frames by said counterweight guide rails; and car and counterweight buffer assemblies, each positioned between its respective guide rails and held in releasable engagement therewith, each of said buffer assemblies having a buffer mounted atop a substantially rectangular buffer frame at the corners of which, and extending outwardly therefrom, are notched guide shoes for cooperation with the respective guide rails; each buffer assembly including a pair of rail engagement assemblies, one mounted at each upper corner of its respective frame, each rail engagement assembly comprising a safety block having in the outer face thereof a roller retaining cavity receiving the guide web of its respective guide rail, a roller within said cavity, a lever arm pivotally connected at a point intermediate its ends to said buffer frame, a linkage rod, one end of which is connected to said roller and the other end of which is connected to one end of said lever arm, the other end of said lever arm being spring biased, thereby urging said roller into engagement with its respective guide rail web and one of the walls of its cavity; and an engagement releasing bracket mounted on said buffer frame for holding said roller out of engagement with its guide rail web against the tension of said spring biased lever arm.
 9. A method of providing passenger elevator service into the unaligned steelwork of a building under construction, said building having a framework with a plurality of horizontal structural elements which define a vertical air shaft and a plurality of floor levels, said method comprising the steps of placing a pair of substantially parallel horizontally disposed, vertically flexible members on the horizontal structural elements which define predetermined ones of said plurality of floor levels; disposing each member of each of said pairs in substantial vertical alignment with and with its longitudinal axis substantially coplanar with and parallel to that of the corresponding members of the other such pairs thereby forming two sets of said members; securing said sets of members to said horizontal structural elements; fastening an elevator car guide rail, comprising a plurality of interconnected rail sections, to the members of each of said sets thereby interconnecting the separate members of each of said sets and forming a temporary hoistway; releasably engaging a buffer assembly including an elevator car buffer to said elevator car guide rails sufficiently to remain stationary under the application of forces to said buffer resulting from the overtravel of its elevator car, thereby establishing a lower terminal for said elevator car; installing traction elevator equipment including an elevator car operable to travel in said temporary hoistway; raising, as building construction progresses upwardly, said buffer assembly to establish a higher lower terminal for said elevator car; and removing portions of said temporary hoistway structure then located below said higher lower terminal. 